固相萃取-高效液相色谱-串联质谱联用测定竹笋中残留的7种杀虫剂农药

建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时测定竹笋中丁烯氟虫腈、毒死蜱、氯虫苯甲酰胺、氟虫腈、吡虫啉、茚虫威和辛硫磷7种农药残留的分析方法。样品用乙腈提取后,经PSA固相萃取小柱净化,采用Atlantis T3色谱柱分离,以0.1%甲酸水溶液(含5 mmol/L乙酸铵)和乙腈为流动相,梯度洗脱分离,在电喷雾离子源正、负离子模式下采用质谱多反应监测(MRM)模式检测。结果表明,7种农药在10～100 μg/L范围内具有良好的线性关系(相关系数r为0.9900～0.9994); 4、8、32 μg/kg添加水平下的平均回收率为76.0%～102.6%;相对标准偏差为3.2%～11.0%;7种农药的检出限为0.02～0.5 μg/kg,定量限为0.08～1.5 μg/kg。该方法准确度、灵敏度高,简单、快速,可满足竹笋中7种杀虫剂残留同时检测的要求。     

QuEChERS前处理联合UPLC–MS/MS法检测花生中22种农药残留

建立了Qu ECh ERS(Quick,Easy,Cheap,Effective,Rugged,Safe)前处理联合UPLC–MS/MS法检测花生中22种农药残留的方法。样品用10 m L乙腈提取,以多壁碳纳米管、N-丙基乙二胺为吸附剂,对2 m L提取液进行净化,净化液稀释至2倍体积,以MRM扫描方式、正负离子模式同时分析。22种农药在10,20,50μg/kg 3个添加水平下,平均回收率为70.6%~121.2%,相对标准偏差小于10%(n=6);多菌灵、抗蚜威、扑草净在0.05~10μg/L,啶虫脒、氟虫腈砜、苯醚甲环唑、哒螨灵、嘧霉胺、嘧菌酯在0.5~20μg/L,烯酰吗啉、噻虫嗪、氟啶脲、灭幼脲、吡虫啉、甲维盐、除虫脲、氟虫腈、氟甲腈、氟虫腈亚砜、咪鲜胺、二甲戊灵在0.5~50μg/L之间,阿维菌素在0.5~100μg/L范围内线性良好,相关系数r2均大于0.995 0。22种农药的定量限在2μg/kg以下,远低于各待测农药最高残留限量标准(MRL)。该法适于花生中农药残留的同时快速检测。     

韭菜中吡虫啉和啶虫脒残留的微波处理-逆固相分散法净化及液相色谱检测

建立了韭菜中两种烟碱类农药吡虫啉和啶虫脒残留的快速检测方法.韭菜样本用微波炉加热处理,使酶钝化消除含硫基质干扰,然后用乙腈提取、逆固相分散净化,用反相高效液相色谱-二极管阵列检测器检测.在0.05～2.0 mg/kg添加水平范围内,吡虫啉的平均添加回收率在95.2%～105.3%之间;相对标准偏差在0.8%～7.8%之间;啶虫脒的平均添加回收率在97.4%～108.8%之间;相对标准偏差在1.3%～8.3%之间.本方法对吡虫啉的检出限(LOD)为0.0078 mg/kg,定量检出限(LOQ)为0.026 mg/kg;对啶虫脒的检出限为0.0075 mg/kg,定量检出限为0.025 mg/kg.     

多重吸附同步净化-气相色谱-质谱法测定干性样品中丁烯氟虫腈的残留量

建立了干性样品中丁烯氟虫腈残留量的多重吸附同步净化(MASP)-气相色谱-质谱检测方法。前处理以1%乙酸-乙腈提取样品,应用MASP法对样品同时进行提取、盐析和净化,并利用气相色谱-质谱仪在选择离子扫描(SIM)模式下进行检测,以基质匹配标准溶液外标法定量。结果表明:丁烯氟虫腈在2~100 μg/L范围内线性关系良好,相关系数(r²)不小于0.999;在2~10 μg/kg添加水平范围内,丁烯氟虫腈的平均回收率为92.2%~97.5%,相对标准偏差(RSD, n=6)为2.69%~5.21%;方法检出限(S/N=3)为2 μg/kg;定量限(S/N=10)为6 μg/kg。本方法操作简便、快速、准确,可用于干性样品中丁烯氟虫腈的日常检测。同时,对丁烯氟虫腈的裂解机理进行了探讨。     

固相微萃取-气相色谱法和气相色谱-质谱法测定茶叶中氟虫腈及其代谢物残留

基于固相微萃取-气相色谱(SPME-GC)建立了检测茶叶中氟虫腈及其代谢物(脱亚硫酰基氟虫腈、硫化氟虫腈、氟虫腈砜、酰胺氟虫腈)残留的分析方法。实验中采用85 μm聚丙烯酸酯(PA)萃取头,萃取温度为60 ℃,萃取缓冲体系的pH值为9。当添加水平为2～10 μg/kg时,回收率在71.2%～109.3%之间,相对标准偏差(RSD)在1.2%～7.1%之间。方法的检出限(LOD)和定量限(LOQ)分别在0.3～1.2 μg/kg和1.0～4.0 μg/kg之间。对所建立的方法采用气相色谱-质谱(GC-MS)进行确证,结果令人满意。本方法灵敏度、精密度和LOD均符合残留分析要求,具有快速、灵敏度高的特点,适合于茶叶中氟虫腈及其代谢物残留的痕量分析。     

在线净化-液相色谱-串联质谱法测定茶叶中5种烟碱类农药残留

建立了在线净化-液相色谱-串联质谱测定茶叶中吡虫啉、啶虫脒、噻虫啉、噻虫嗪和噻虫胺5种常见烟碱类农药残留量的方法。样品经水浸泡、乙腈提取和在线净化后,用液相色谱-串联质谱测定。结果表明,本方法对5种烟碱类农药的定量限均为0.01 mg/kg。5种烟碱类农药在1.0~10 μ g/L范围内具有良好的线性关系,相关系数均大于0.998。在0.01、0.02和0.05 mg/kg的添加水平下,回收率为68.0%~113.2%,相对标准偏差为3.2%~7.6%。本方法简便、快速、准确,适用于茶叶样品中烟碱类农药残留量的检测。     

QuEChERS/超高效液相色谱-串联质谱法测定动物源食品中氟啶虫胺腈和氟吡呋喃酮残留量

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定动物源食品中氟啶虫胺腈和氟吡呋喃酮残留量的方法。样品中的氟啶虫胺腈和氟吡呋喃酮经乙腈超声提取和分散固相萃取净化,净化后的样液经滤膜过滤后采用UPLC-MS/MS法测定。以乙腈和5 mmol/L乙酸铵-0.1%甲酸水溶液为流动相,采用ACQUITY UPLC^? HSS T3色谱柱(2.1 mm×100 mm,1.8μm)分离,电喷雾离子化、正离子扫描方式和多反应监测模式检测,外标法定量。结果表明,氟啶虫胺腈和氟吡呋喃酮在0.25～20.0μg/L范围内线性关系良好,相关系数(r²)分别为0.999 3和0.999 1,方法检出限和定量下限分别为1.0μg/kg和5.0μg/kg。实际样品的平均加标回收率为90.1%～113%,相对标准偏差(RSD)为2.5%～7.8%。该方法快速简便、准确度和灵敏度高、重现性好,可满足动物源食品中氟啶虫胺腈和氟吡呋喃酮残留的检测要求。     

稳定同位素稀释超高效液相色谱-串联质谱法测定饲料中氟虫腈及其代谢物

建立了超高效液相色谱-串联质谱测定饲料中氟虫腈及其代谢物氟甲腈、氟虫腈硫醚和氟虫腈砜的方法。样品经纯水和乙腈超声提取后加入氯化钠盐析,采用QuEChERS技术净化,以Waters HSS T3 C₁₈色谱柱分离,甲醇和纯水为流动相进行梯度洗脱,在多反应监测、负离子模式下进行检测,内标法定量。氟虫腈及其代谢物在各自的范围内呈良好的线性关系,相关系数均大于0.9998;氟虫腈及其代谢物的检出限和定量限分别为0.05 μg/kg和0.2 μg/kg,加标回收率为92.3%~105.4%,相对标准偏差为0.9%~2.3%（n=5）。该法样品前处理过程简单,净化效果好,灵敏度高,适用于各种饲料中氟虫腈及其代谢物含量的测定。     

固相萃取-高效液相色谱-串联质谱法同时测定银耳中的8种农药残留

建立了同时测定银耳中吡虫啉、啶虫脒、异丙威、丁硫克百威、克百威、甲胺磷、乙酰甲胺磷和咪鲜胺8种常见农药残留的固相萃取-高效液相色谱-串联质谱分析方法。5 g样品,加入1 g NaCl,用乙酸乙酯提取,提取液通过C18柱固相萃取净化后,以Phenomenex Luna C8色谱柱(150 mm×2.0 mm×3.0μm)分离,流动相A为含0.1%甲酸-5 mmol/L NH_4Ac溶液,流动相B为乙腈,梯度洗脱。质谱采用多反应监测(MRM)模式检测,外标法定量。结果显示:吡虫啉在1.0～1 000.0μg/L,啶虫脒、异丙威、丁硫克百威、克百威和咪鲜胺在1.0～500.0μg/L,甲胺磷和乙酰甲胺磷在1.0～250.0μg/L范围内线性良好,相关系数(r~2)均大于0.995;检出限为0.01～0.30μg/kg,定量限为0.03～1.00μg/kg。在低、中、高3个水平加标的回收率为70.1%～106.4%,相对标准偏差(RSD)为3.97%～13.68%。实际样品检测结果表明该方法稳定、准确、可靠。     

气相色谱-三重四极杆质谱法快速检测鸡蛋中氟虫腈及其代谢物

建立了QuEChERS前处理技术结合气相色谱-三重四极杆质谱（GC-MS/MS）分析鸡蛋中氟虫腈及其代谢物的快速检测方法。样品由乙腈提取,然后经150 mg MgSO₄脱水和50 mg N-丙基乙二胺（PSA）、50 mg C18净化,采用农药残留专用柱（TR-Pesticide Ⅱ）进行气相色谱分离,以定时反应监测（timed-SRM）模式进行检测,基质曲线外标法定量。结果表明,氟虫腈及其代谢物在1.0~200 μg/L范围内呈良好线性,线性相关系数（R²）均大于0.999,定量限为0.5~1.0 μg/kg;氟虫腈及其代谢物在3个添加水平（2、5和10 μg/kg）下的加标回收率为87.8%~111.5%,相对标准偏差（RSD,n=3）为2.0%~9.2%,该方法能满足欧盟规定的鸡蛋中氟虫腈及其代谢物的残留检测限量要求。     

Applications of LC/ESI-MS/MS and UHPLC/Qq-TOF-MS for the determination of 141 pesticides in tea

This paper presents the applications of LC-electrospray ionization (ESI)/MS/MS and ultra-HPLC (UHPLC)/ESI quadrupole (Qq)-time-of-flight (TOF) MS for the determination of 141 pesticides in tea. Pesticides were extracted and cleaned up from tea with a modified quick, easy, cheap, effective, rugged, and safe method using graphitized carbon black and primary-secondary amine sorbents. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 microg/kg. The LC/ESI-MS/MS served as a reliable tool to quantify the pesticides due to its superior sensitivity and good repeatability. Its method performance characteristics that include overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. About 87% of the pesticides had recoveries between 81 and 110%; 94% had an intermediate precision < or = 20%; and 90% showed measurement uncertainty < or = 40%. About 92% of the pesticides were able to be detected at 5 microg/kg with an S/N > or = 3. The UHPLC/Qq-TOF-MS showed much less sensitivity and poorer repeatability compared to the LC/ESI-MS/MS, and, therefore, it was primarily used for confirmatory purposes based on the accurate mass measurement and isotopic patterns.     

Determination of neonicotinoid pesticides residues in agricultural samples by solid-phase extraction combined with liquid chromatography-tandem mass spectrometry

This work reports a new sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, confirmation and quantification of six neonicotinoid pesticides (dinotefuran, thiamethoxam, clothiandin, imidacloprid, acetamiprid and thiacloprid) in agricultural samples (chestnut, shallot, ginger and tea). Activated carbon and HLB solid-phase extraction cartridges were used for cleaning up the extracts. Analysis is performed by LC-MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Quantification was carried by the internal standard method with D(4)-labeled imidacloprid. The method showed excellent linearity (R(2)≥0.9991) and precision (relative standard deviation, RSD≤8.6%) for all compounds. Limits of quantification (LOQs) were 0.01 mg kg(-1) for chestnut, shallot, ginger sample and 0.02 mg kg(-1) for tea sample. The average recoveries, measured at three concentrations levels (0.01 mg kg(-1), 0.02 mg kg(-1) and 0.1 mg kg(-1) for chestnut, shallot, ginger sample, 0.02 mg kg(-1), 0.04 mg kg(-1) and 0.2 mg kg(-1) for tea sample), were in the range 82.1-108.5%. The method was satisfactorily validated for the analysis of 150 agricultural samples (chestnut, shallot, ginger and tea). Imidacloprid and acetamiprid were detected at concentration levels ranging from 0.05 to 3.6 mg kg(-1).     

超高效液相色谱-串联质谱法同时测定茶叶中11种植物生长调节剂及吡虫啉、啶虫脒的残留

建立了超高效液相色谱-串联质谱法同时快速测定茶叶中11种植物生长调节剂(PGRs)及吡虫啉、啶虫脒的方法.样品经乙腈-甲酸溶液(99∶1, V/V)均质提取,采用C18、强阴离子交换剂(SAX)、 N-丙基乙二胺(PSA)和无水MgSO4混合吸附剂分散萃取处理,以HSS T3色谱柱分离,采用电喷雾(ESI)正负离子同时扫描和可编程多反应监测模式(SMRM)检测,基质匹配溶液外标法定量.6-苄氨基嘌呤、多效唑、烯效唑、氯吡脲、甲哌啶、吡虫啉、啶虫脒在1～200 μg/L和2,4-二氯苯氧乙酸、对氯苯氧乙酸、赤霉素、吲哚乙酸、萘乙酸、吲哚丁酸在5～1000 μg/L范围内线性良好(R2>0.99).13种化合物加标回收率在73.1％～108.9％之间,RSD (n=6)值在0.6％～8.0％之间,方法检出限(LOD, S/N=3)和定量限(LOQ, S/N=10)分别为0.18～9.68 μg/kg和0.61～32.26 μg/kg.本方法简便、稳定、灵敏,能够满足实际检测需求.     

茶叶中敌敌畏残留量检测的不确定度评定

依据SN/T 1950-2007方法,对茶叶中敌敌畏残留量的测量不确定度进行分析和评定.该检测过程所产生的测量不确定度主要来源于测量重复性、标准物质纯度、标准物质称量、标准溶液稀释、样品称量、定容体积、标样溶液峰面积和样品溶液峰面积的测量.分析结果表明:茶叶中敌敌畏残留量为0.050 mg/kg时,其扩展不确定度为0....     

气相色谱-串联质谱双内标法测定茶叶中53种农药残留

建立了气相色谱-串联质谱（GC-MS/MS）动态多反应离子监测（dMRM）模式,结合串联双色谱柱检测茶叶中53种农药残留量的分析方法。样品中加入QuEChERS缓冲盐,用乙腈提取,采用石墨化炭黑/氨基柱（ENVI-Carb/NH₂）净化。为减少农药在GC-MS/MS分析中基质效应的影响,在标准溶液中加入古洛糖酸内酯和山梨醇作为保护剂,用蒽醌-D8和磷酸三苯酯作双内标定量。结果表明,除了氯氰菊酯的线性范围是40~1000 μg/L外,其他52种农药的线性范围均为20~500 μg/L,线性关系良好,相关系数均大于0.99;有28种农药的定量限（LOQ）小于10 μg/kg,其余25种农药的定量限为10~20 μg/kg;加标回收率为72.5%~130.9%;相对标准偏差（RSD）为0.4%~19.4%。该方法能有效地减少茶叶在GC-MS/MS上的基质效应,操作简单快速,灵敏度和选择性高,适用于农药残留的日常检测。     

Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables

This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 μg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision ≤20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty ≤40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision ≤20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty ≤40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.     

GC-NCI-MS分析茶叶中17种有机氯和拟除虫菊酯农药残留

建立了茶叶试样中17种农药残留(8种有机氯和9种拟除虫菊酯农药)的气相色谱-负化学离子源-质谱(GC-NCI-MS)联用的分析方法.茶叶试样用V(正己烷)/V(丙酮)=1/1混合提取剂超声提取,经Florisil硅藻土和中性氧化铝混合层析柱净化后,以环氧七氯为内标物,采用GC-NCI-MS的选择离子监测方式(SIM)分析;探讨了茶叶试样的基体诱导色谱响应增强影响所产生的分析误差及其减小的措施,用空白试样基体匹配校准曲线法(MC法)定量分析.当加标质量浓度水平为20,50和200μg/kg时,加标回收率为67.9%~129%,相对标准偏差为1.0%~20%,除氯菊酯农药的检出限为8.3μg/kg外,其余大部分农药的检出限均小于1.0μg/kg,线性范围为10~500μg/kg,相关系数均大于0.996,此方法成功地应用于茶叶试样中痕量农药残留的分析.     

加速溶剂萃取-超高效液相色谱-串联质谱法测定茶叶中拟除虫菊酯类农药残留

建立了加速溶剂萃取（ASE）-超高效液相色谱（UPLC）-串联质谱法（MS/MS）测定茶叶中拟除虫菊酯类农药残留的方法。ASE萃取温度为80 ℃，萃取压力为10.34 MPa，以正己烷-丙酮（2∶1，v/v）为溶剂静态萃取5 min，循环一次。萃取液浓缩后经GCB/NH₂-Florisil柱净化，UPLC分离，MS/MS正离子扫描（ESI⁺）、多反应离子监测（MRM）模式进行分析，外标法定量。线性回归分析表明：10种拟除虫菊酯的浓度与其峰面积的线性关系显著，相关系数（r）均不小于0.9995，检出限（LOD）在0.5~5.0 μg/kg之间，定量限（LOQ）在1.6~16.6 μg/kg之间；在定量限、0.4 mg/kg以及最高残留限量（MRL，无MRL的加入1 mg/kg）3个水平进行添加回收试验（n=7），回收率为68.7%~103.8%，RSD为0.8%~13.2%。该方法前处理简单，耗时短，灵敏度和准确度高，可满足茶叶中痕量拟除虫菊酯类农药残留测定的要求。